4/5 i dont make it 5/5 because i dont like how there are max limits to amount of items lvl of items and enemy strength another thing is all missiles go after 1 target and dont change target after it dies.
oh and on the last lvl i had a lvl 11, 2 8's, and about 4 lvl 7 mana steal gems in traps. and i found there is a max rate of fire for towers.(not sure about traps)
the skill path i used is starting mana-critical hit mastery-mana steal mastery- the ones for mana per kill and gem cost-dual gem mastery- then the four rate/max damage/min damage/range/then all gem mastery
also armour reduction has highest rate of fire.